pinion and crown wheel differences

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kevlar1981
Posts: 18
Joined: 07 Aug 2014 09:47 pm

pinion and crown wheel differences

Post by kevlar1981 » 04 Feb 2015 10:52 pm

Hi guys,. I'm looking at fitting a 5 speed to my 340. I have got a box with a 3.82 ratio and the original 4 speed it the 3.64, now because I run 13" wheels with only 55 profile my cruise speed is low so was wondering about swapping the ratios over to give better cruise with the new 5 speed.
So my main question is are the pinion gears the same pitch and number of teeth between the two diffs or would I have to swap both crown and pinion gears over?
Thanks guys.
Also I have looked for an answer in the old threads but can't find anything about the pinion gear teeth number

derskine
Posts: 199
Joined: 29 Sep 2013 10:38 pm

Re: pinion and crown wheel differences

Post by derskine » 04 Feb 2015 11:06 pm

4 speed diffs don't fit 5 speed boxes I don't think unfortunately.
I'd think you'll be fine with the 5 speed diff ratio though.
Last edited by derskine on 05 Feb 2015 08:57 am, edited 1 time in total.
1984 Volvo 360 GLE Saloon
1987 Volvo 340 1.7GL

Additionally -

1966 Ford MK1 Cortina
1971 Hillman Imp
1984 Renault 18 GTD

macplaxton
Posts: 3283
Joined: 09 Feb 2008 02:29 am

Re: pinion and crown wheel differences

Post by macplaxton » 05 Feb 2015 05:09 am

kevlar1981 wrote:Also I have looked for an answer in the old threads but can't find anything about the pinion gear teeth number
Must look harder ;) Here's something about the pinion gear teeth number: viewtopic.php?f=13&t=3544&start=45

From the Green Book: viewtopic.php?f=36&t=7262

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V300_man_gearbox_ratios by macplaxton, on Flickr
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V300_man_gearbox_final_drive_ratios by macplaxton, on Flickr
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V300_man_gearbox_final_drive_features by macplaxton, on Flickr

From back of a fag packet (or robbed from Mac*):

3.91:1 (43/11)
3.82:1 (42/11)
3.64:1 (40/11)
3.45:1 (38/11)
3.36:1 (37/11)
3.27:1 (36/11)

For any other ratio, work it out yourself...
kevlar1981 wrote:now because I run 13" wheels with only 55 profile
More info please. I guess it could be anywhere between 165 and 205mm?

Do the sums now and work out what you'd be happy with and then work out what bits you can use/need.
72 DAF 44 Estate 78 Volvo 343DL Black BeautyImageImage
82 Volvo 343DL CVTImageImage 88 Volvo 340DL Diesel

kevlar1981
Posts: 18
Joined: 07 Aug 2014 09:47 pm

Re: pinion and crown wheel differences

Post by kevlar1981 » 05 Feb 2015 09:33 am

Brilliant thanks for that that's just what I wanted to see the pinion gears being the same number of teeth.
Top man sm4

macplaxton
Posts: 3283
Joined: 09 Feb 2008 02:29 am

Re: pinion and crown wheel differences

Post by macplaxton » 05 Feb 2015 11:57 am

Irrespective of tooth-count, crown wheel and pinions are made and sold as matching sets. Just because they have the same number of teeth, doesn't necessarily mean they are physically the same size either.

Always change crown wheel and pinions as a matched set. Doing otherwise is pure folly.


To steal a line from Mac, "But then what do I know ??" :wink:
72 DAF 44 Estate 78 Volvo 343DL Black BeautyImageImage
82 Volvo 343DL CVTImageImage 88 Volvo 340DL Diesel

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